Search results for " film"

showing 10 items of 3842 documents

<title>Electrochromism of W-oxide-based films: some theoretical and experimental results</title>

1995

We survey some recent work related to electrochromic W-oxide-based thin films. The electronic structure of cubic (perovskite) WO3 and HWO3 was calculated from first principles. It was found, among other things, that hydroxide formation was energetically favored. Experimental studies were made on films prepared by reactive magnetron sputtering in Ar + O2 with and without CF4 addition and substrate bias. Structural studies by atomic force microscopy, x-ray diffraction, infrared reflectance spectroscopy, and Raman spectroscopy indicated that the electron bombardment associated with a positive substrate bias led to grain growth and partial crystallization while maintaining a high density of W e…

symbols.namesakeMaterials scienceSputteringScanning electron microscopeElectrochromismAnalytical chemistrysymbolsSubstrate (electronics)Thin filmSputter depositionRaman spectroscopyPerovskite (structure)SPIE Proceedings
researchProduct

Effect of Fe-incorporation on Structural and Optoelectronic Properties of Spin Coated p/n Type ZnO Thin Films

2020

symbols.namesakeRadiationMaterials sciencebusiness.industrysymbolsOptoelectronicsGeneral Materials ScienceThin filmCondensed Matter PhysicsbusinessSpin (physics)Raman scatteringJournal of Nano- and Electronic Physics
researchProduct

Towards Controlled Synthesis of Water-Soluble Gold Nanoclusters : Synthesis and Analysis

2019

Water-soluble gold nanoclusters with well-defined molecular structures and stability possess particular biophysical properties making them excellent candidates for biological applications as well as for fundamental spectroscopic studies. The currently existing synthetic protocols for atomically monodisperse thiolate-protected gold nanoclusters (AuMPCs) have been widely expanded with organothiolates, yet the direct synthesis reports for water-soluble AuMPCs are still deficient. Here, we demonstrate a wet-chemistry pH-controlled synthesis of two large water-soluble nanoclusters utilizing p-mercaptobenzoic acid (pMBA), affording different sizes of plasmonic AuMPCs on the preparative scale (∼7 …

synthesis02 engineering and technology010402 general chemistry01 natural scienceskultaQuantitative Biology::Cell BehaviorNanoclusterssynteesiPhysical and Theoretical Chemistryta116Condensed Matter::Quantum Gaseskemiallinen synteesita114Condensed Matter::OtherChemistryCondensed Matter::Mesoscopic Systems and Quantum Hall Effect021001 nanoscience & nanotechnology0104 chemical sciencesSurfaces Coatings and FilmsElectronic Optical and Magnetic Materialsstomatognathic diseasesGeneral EnergyWater solubleChemical engineeringnanohiukkaset0210 nano-technologygold nanoclustersThe Journal of Physical Chemistry C
researchProduct

An Easy Route Towards Regioselectively Difunctionalized Cyclens and New Cryptands.

2006

Reductive amination of various aldehydes with cyclen represents a very convenient method for the synthesis of a wide range of 1,7-difunctionalized cyclens, as well as new cryptands.

synthesisStereochemistry[CHIM.ORGA]Chemical Sciences/Organic chemistry010405 organic chemistryCryptandMetals and AlloysGeneral ChemistryGeneral Medicine010402 general chemistry01 natural sciencesCombinatorial chemistryReductive aminationCatalysisSurfaces Coatings and FilmsElectronic Optical and Magnetic Materialscyclen0104 chemical sciences3. Good healthchemistry.chemical_compoundCyclenchemistry[ CHIM.ORGA ] Chemical Sciences/Organic chemistryMaterials ChemistryCeramics and CompositesComputingMilieux_MISCELLANEOUSChemInform
researchProduct

Isophorone on Au/MgO/Ag(001) : Physisorption with Electrostatic Site Selection

2017

We report a computational study of isophorone C9H14O adsorption on a Ag(001)-supported ultrathin MgO film with Au adatoms and clusters employing density functional theory calculations. The calculations show that the keto form of isophorone is more stable than the enol tautomers both in gas phase and on the MgO/Ag(001) surface. The interaction between the keto isophorone and step and terrace sites of MgO/Ag(001) displays long interaction distances, relatively weakly exothermic adsorption energies, lack of charge transfer, and minor changes in the density of states, all of which indicate that the molecule merely physisorbs on the surface. The step sites are energetically preferred adsorption …

ta114Chemistry02 engineering and technology021001 nanoscience & nanotechnologyPhotochemistry01 natural sciencesTautomerEnolSurfaces Coatings and FilmsElectronic Optical and Magnetic Materialschemistry.chemical_compoundCrystallographyGeneral EnergyAdsorptionPhysisorptionisophorone adsorption0103 physical sciencesDensity of statesMoleculeDensity functional theoryPhysical and Theoretical Chemistry010306 general physics0210 nano-technologyta116IsophoroneJournal of Physical Chemistry C
researchProduct

Theoretical Analysis of the M12Ag32(SR)404– and X@M12Ag32(SR)304– Nanoclusters (M = Au, Ag; X = H, Mn)

2014

We analyze the electronic structure and optical properties of the recently reported, structurally known M12Ag32(SR)304– clusters (M = Au, Ag) by using density functional theory and time-dependent density functional perturbation theory. Effects of the chemical changes in the metal core, charge of the cluster, and nature of the thiolate ligand on the electronic structure and optical absorption are reported. In addition, doping the metal core with a magnetic transition metal atom (Mn) or hydrogen (protons) is discussed. Although all these clusters can be considered as 18-electron superatoms with a shell configuration 1S2 1P6 1D10, we find that the optical spectrum is sensitive to the charge st…

ta114ChemistryDopingnanoclustersElectronic structurechemistrySurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsNanoclustersMetalCrystallographyGeneral EnergyTransition metalvisual_artAtomCluster (physics)visual_art.visual_art_mediumDensity functional theoryPhysical and Theoretical ChemistryAtomic physicsta116physicsJournal of Physical Chemistry C
researchProduct

Ultrafast electronic relaxation and vibrational cooling dynamics of Au 144(SC2H4Ph)60 nanocluster probed by transient mid-IR spectroscopy

2014

Energy relaxation dynamics of a gold nanocluster with atomically precise composition, Au144(SC2H4Ph)60, is studied by transient mid-IR spectroscopy. The experiment is designed to simultaneously pro...

ta114ChemistryDynamics (mechanics)Analytical chemistryMolecular physicsSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsGeneral EnergyVibrational energy relaxationRelaxation (physics)Transient (oscillation)Physical and Theoretical ChemistrySpectroscopyUltrashort pulseta116The Journal of Physical Chemistry C
researchProduct

TDDFT Analysis of Optical Properties of Thiol Monolayer-Protected Gold and Intermetallic Silver–Gold Au144(SR)60 and Au84Ag60(SR)60 Clusters

2014

The optical absorption spectra of atomistic model structures for experimentally isolated all-gold Au144(SR)60 and intermetallic Au84Ag60(SR)60 clusters are systematically analyzed from linear-response time-dependent density functional theory (LR-TDDFT) and time-dependent density functional perturbation theory (TD-DFPT) calculations. The computed spectra, utilizing the atomistic model for Au144(SR)60 published by us in 2009, reproduce closely the experimental observations for corresponding isolated compounds, reported previously by Kumara and Dass in 2011. A collective dipole oscillation within the metal cores of the all-gold and intermetallic clusters is formed as response to light in the v…

ta114ChemistryIntermetallicTime-dependent density functional theoryMolecular physicsSpectral lineSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsMetalDipoleGeneral Energyvisual_artMonolayervisual_art.visual_art_mediumDensity functional theoryPhysical and Theoretical ChemistrySurface plasmon resonanceAtomic physicsta116The Journal of Physical Chemistry C
researchProduct

Optical Properties of Monolayer-Protected Aluminum Clusters: Time-Dependent Density Functional Theory Study

2015

We examine the electronic and optical properties of experimentally known monolayer-protected aluminum clusters Al4(C5H5)4, Al50(C5Me5)12, and Al69(N(SiMe3)2)183– using time-dependent density functional theory. By comparing Al4(C5H5)4 and the theoretical Al4(N(SiMe3)2)4 cluster, we observe significant changes in the optical absorption spectra caused by different hybridization between metal core and ligands. Using these initial observations, we explain the calculated spectra of Al50(C5Me5)12 and Al69(N(SiMe3)2)183–. Al50(C5Me5)12 shows a structured spectrum with clear regions of low-intensity core-to-core transitions followed by high-intensity ligand-to-core transitions due to its high symmet…

ta114Chemistrychemistry.chemical_elementTime-dependent density functional theorySpectral lineSymmetry (physics)3. Good healthSurfaces Coatings and FilmsElectronic Optical and Magnetic Materialsaluminum clustersMetalCrystallographytime-dependent density functional theoryGeneral EnergyAluminiumvisual_artMonolayervisual_art.visual_art_mediumCluster (physics)Density functional theoryPhysical and Theoretical Chemistryta116Journal of Physical Chemistry C
researchProduct

The Role of the Anchor Atom in the Ligand of the Monolayer-Protected Au25(XR)18– Nanocluster

2015

We present a density functional theory (DFT) investigation on the role of the anchor atom and ligand on the structural, electronic, and optical properties of the anionic Au25(XR)18– nanocluster (X = S, Se, Te; R = H, CH3, and (CH2)2Ph). Substituting the anchor atom with other group 16 elements induces subtle changes in the Au–Au and Au–X bond lengths and polarization of the covalent bond. The changes in the electronic structure based on substituting both the anchor and R groups are presented through careful analysis of the density of states and theoretical determined optical spectra. We give a detailed side-by-side comparison into the structural, electronic, and optical properties of Au25(X…

ta114LigandChemistryligandsElectronic structureanchor atomsSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsBond lengthCrystallographyGeneral EnergyCovalent bondComputational chemistryAtomMonolayerDensity of statesDensity functional theoryPhysical and Theoretical Chemistryta116gold nanoclustersJournal of Physical Chemistry C
researchProduct